Examining the Relationship between Household Air Pollution and Infant Nasal Carriage

摘要

Background/Aim: Pneumonia, the leading cause of childhood mortality worldwide, is associated with household air pollution (HAP) exposure. Mechanisms between HAP and pneumonia are poorly understood, but the Randomized Exposure Study of Pollution Indoors and Respiratory Effects trial in Guatemala identified severe pneumonia as more likely of bacterial, rather than viral, etiology. Our research seeks to confirm relationships between HAP and infant bacterial carriage, specifically among those diagnosed with pneumonia. Methods: Data were collected through the Ghana Randomized Air Pollution Study (GRAPHS), which recruited mother-infant pairs until the child's first birthday. Improved biomass, LPG, or 3-stone (baseline) cookstoves were randomly assigned to participants. The current analysis is restricted to LPG and 3-stone arms. Carbon monoxide (CO) exposures were measured for each infant and fieldworkers conducted surveillance for pneumonia. Cases were sent for treatment and nasopharyngeal swabs. Age and sex-matched controls were swabbed. Swabs were analysed with MassTag PCR for common infections. Statistical analyses included group-wise comparisons of microbial pathogens by study arm. At study completion, the association between CO-levels and specific microbes will be analysed. Results: Preliminary analysis demonstrates participants in the 3-stone arm have higher microbial levels than the LPG intervention arm (p<0.0001) (N=198). This difference appears driven by bacterial (p<0.0001) rather than viral levels (non-significant) among 3-stone participants. Bacterial-level differences are consistent when stratifying by cases (p<0.0001) and controls (p=0.0049). Forthcoming analysis will assess the effects on specific microbe species. Conclusions: Findings could strengthen knowledge of pneumonia etiology. Childhood pneumonia is a grave public health concern and these data could inform public health efforts, including HAP interventions or vaccination programs.